"There has been no leakage of the question paper. All the seals (of packed question papers) have been found intact at all the exam centres," the Board said in its official statement.

"During the process of examination, however, at local level, some miscreants tried to play mischief by circulating messages through WhatsApp and other social media to disturb the sanctity of examinations," the CBSE said.

The CBSE has also decided to lodge an FIR against those who circulated the rumours.

Earlier, Delhi Deputy Chief Minister Manish Sisodia ordered the Directorate of Education to investigate and lodge a complaint with the CBSE.

This followed media reports that the question paper was leaked on WhatsApp.

Sisodia said swift action must be taken so that hard-working students do not suffer due to the "negligence of the Central Board of Secondary Education".